Ohm's Law states that the current through a conductor is proportional to the voltage across it: V = I × R, where V is voltage (volts), I is current (amperes), and R is resistance (ohms).

How is power calculated?

Power (P) = V × I = I² × R = V² / R. This is the Joule heating formula and gives the rate of energy dissipation in watts.

Can I calculate power with just two values?

Yes. With any two of V, I, R you can derive the third and then calculate power. This calculator solves for all four automatically.

Ohm's Law Calculator

Calculate voltage, current, resistance, or power using Ohm's Law.

Solve for

Voltage (V)

Current (A)

Resistance (Ω)

Power (W)

Voltage

12.00 V

Current

2.000 A

Resistance

6.000 Ω

Power

24.00 W

V = I × RI = V / RR = V / IP = V × I = I² × R = V² / R

Instant Ohm's Law calculations

Enter any two electrical values and this tool calculates the remaining variables. Essential for electronics design and troubleshooting.

Frequently asked questions

What is Ohm's Law?: Ohm's Law states that the current through a conductor is proportional to the voltage across it: V = I × R, where V is voltage (volts), I is current (amperes), and R is resistance (ohms).
How is power calculated?: Power (P) = V × I = I² × R = V² / R. This is the Joule heating formula and gives the rate of energy dissipation in watts.
Can I calculate power with just two values?: Yes. With any two of V, I, R you can derive the third and then calculate power. This calculator solves for all four automatically.

Instant Ohm's Law calculations

Frequently asked questions

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